ACT SSC Biology · Unit 1
ACT SSC Biology Unit 1: Biodiversity and Connectedness — Flashcards & Quiz
ACT SSC Biology Unit 1 examines biodiversity and the connectedness of living organisms within ecosystems. In the BSSS framework, this unit explores classification, ecosystem dynamics, species interactions and the factors that influence biodiversity. These flashcards and quiz questions help you revise the key concepts tested in ACT assessments.
Key Terms
- Biodiversity
- The variety of life forms at genetic, species and ecosystem levels; a core concept in the BSSS Biology framework for understanding ecosystem resilience and connectedness in ACT SSC assessments.
- Taxonomic Classification
- The hierarchical system used to group organisms by shared characteristics and evolutionary ancestry, from domain to species, as required in BSSS school-based assessment tasks.
- Ecological Niche
- The specific role and set of conditions an organism occupies within its ecosystem, including its habitat, diet and interactions; assessed in ACT SSC practical investigations of connectedness.
- Trophic Level
- The position an organism holds in a food chain or web, determining the flow of energy and matter through an ecosystem as examined in BSSS unit score tasks.
- Keystone Species
- A species whose impact on ecosystem structure and function is disproportionately large relative to its abundance; a concept used in BSSS evaluation questions on biodiversity conservation.
- Species Richness
- The number of different species present in a given area, used as one measure of biodiversity in BSSS field investigation reports and data analysis tasks.
- Ecological Succession
- The gradual process of change in species composition and community structure over time following a disturbance, assessed in ACT Senior Secondary Certificate ecology modules.
Sample Flashcards
Q1: State the three principles of cell theory.
1) All living things are composed of cells. 2) Cells are the basic structural and functional unit of life. 3) All cells arise from pre-existing cells.
Q2: What is the key structural difference between prokaryotic and eukaryotic cells?
Prokaryotic cells lack a membrane-bound nucleus and organelles; eukaryotic cells have a true nucleus enclosed by a nuclear envelope and membrane-bound organelles.
Q3: Describe the fluid mosaic model of the cell membrane.
The membrane is a phospholipid bilayer with proteins, cholesterol and carbohydrates embedded or attached. "Fluid" because components move laterally; "mosaic" because of the varied protein pattern.
Q4: Define diffusion and give one biological example.
Diffusion is the net movement of particles from a region of high concentration to low concentration down the concentration gradient, requiring no energy.
Q5: What is osmosis?
Osmosis is the net movement of water molecules from a region of low solute concentration to high solute concentration across a selectively permeable membrane.
Q6: Explain facilitated diffusion.
Facilitated diffusion is passive transport of molecules across the membrane through specific carrier or channel proteins, moving down the concentration gradient without energy input.
Q7: How does active transport differ from passive transport?
Active transport moves substances against their concentration gradient (low to high) and requires energy (ATP). Passive transport moves substances down the gradient without energy.
Q8: Define endocytosis and exocytosis.
Endocytosis: the cell membrane folds inward to engulf substances into a vesicle. Exocytosis: vesicles fuse with the membrane to release contents outside the cell.
Sample Quiz Questions
Q1: All living things are composed of one or more cells.
Answer: TRUE
This is the first principle of cell theory. All organisms are made of cells.
Q2: Viruses are considered living organisms under cell theory.
Answer: FALSE
Viruses are not made of cells and cannot reproduce independently. They challenge cell theory boundaries.
Q3: Prokaryotic cells have a membrane-bound nucleus.
Answer: FALSE
Prokaryotic cells lack a membrane-bound nucleus. Their DNA is in a nucleoid region.
Q4: Both prokaryotic and eukaryotic cells contain ribosomes.
Answer: TRUE
Ribosomes are found in all cells — prokaryotic (70S) and eukaryotic (80S) — for protein synthesis.
Q5: The cell membrane is described as "fluid" because its components can move laterally.
Answer: TRUE
Phospholipids and some proteins can drift laterally within the bilayer.
Why It Matters
Biodiversity and Connectedness in ACT SSC Biology Unit 1 establishes the foundational understanding of how living organisms are classified and how they interact within ecosystems. BSSS assessments expect you to explain classification systems, analyse ecological relationships, and evaluate the factors that promote or threaten biodiversity. This unit develops both field investigation skills and theoretical knowledge, as biodiversity surveys, data collection and ecological modelling are frequently assessed. Students who build a strong grasp of species interactions and ecosystem dynamics find that subsequent units on cells, heredity and internal environments make significantly more sense. Classification skills reappear in heredity when tracing evolutionary relationships through phylogenetic trees, and ecosystem dynamics underpin the internal environment unit's treatment of organism interactions. BSSS exam questions on biodiversity commonly require you to interpret ecological data sets, so practise constructing and analysing species diversity indices and food web diagrams under timed conditions.
Key Concepts
Biodiversity and Classification
Organisms are classified into hierarchical groups based on shared characteristics and evolutionary relationships. Understanding taxonomy, binomial nomenclature and the differences between kingdoms prepares you for BSSS questions on how scientists organise and study the diversity of life.
Ecosystem Interactions
Species interact through predation, competition, mutualism, commensalism and parasitism. Understanding these ecological relationships and how energy and matter flow through food webs helps you analyse how changes in one population affect the broader community.
Ecological Connectedness
All organisms are connected through food webs, nutrient cycles and habitat dependencies. BSSS assessments test your ability to trace these connections and predict how disruptions such as habitat loss or species removal cascade through an ecosystem.
Threats to Biodiversity
Habitat destruction, invasive species, climate change and overexploitation are the main threats to biodiversity. Evaluating conservation strategies and understanding the importance of biodiversity for ecosystem resilience are key skills for BSSS evaluation questions.
Common Mistakes to Avoid
- Confusing species richness with species evenness in BSSS biodiversity assessments — richness counts the number of different species while evenness measures how balanced their population sizes are.
- Drawing food webs without indicating the direction of energy flow — BSSS examiners expect arrows pointing from prey to predator, showing the transfer of energy up each trophic level.
- Treating classification as purely memorisation instead of demonstrating understanding of evolutionary relationships, which is what ACT SSC unit score criteria actually reward.
- Failing to include Australian examples in ecological connectedness responses — BSSS assessments specifically value local and regional biodiversity contexts.
Study Tips
- Practise classifying organisms into their taxonomic groups from memory, then check your textbook to reinforce the key characteristics of each kingdom and phylum.
- Create flashcards pairing each ecological relationship type with a real Australian example, reviewing with spaced repetition to build recall.
- Work through food web diagrams by tracing energy flow and predicting cascade effects when one species is removed from the web.
- Use past BSSS practical reports as models for structuring your own biodiversity survey write-ups with clear methods and data analysis.
- Compare the factors promoting and threatening biodiversity using a detailed table to prepare for evaluation questions on conservation strategies.
- Before your exam, work through the practice questions in this set at least twice using spaced repetition. Testing yourself repeatedly is the most effective revision strategy for long-term retention.
Related Topics
Frequently Asked Questions
What does ACT SSC Biology Unit 1 cover?
Unit 1 covers biodiversity, classification of organisms, ecosystem interactions, species connectedness, ecological relationships and the factors that influence biodiversity in Australian and global contexts.
How many flashcards are in this set?
This free set contains 20 flashcards and 20 true/false quiz questions covering all key concepts in Unit 1, aligned to the BSSS Biology framework.
Are these flashcards aligned to the ACT curriculum?
Yes — every flashcard and quiz question is mapped to the BSSS Science Framework for ACT SSC Biology Unit 1.
Last updated: March 2026 · 20 flashcards · 20 quiz questions · Content aligned to the BSSS Framework